In a V-type engine, in which an overhead cam shaft is driven by means of a timing chain, the cylinder block has to be formed with a chain passage through which the timing chain is allowed to pass. At the tensile and slack sides of the chain, arranged in a sliding manner, are two chain guides. The chain guide at the slack side is elastically urged toward the chain by a chain tensioner in order to apply a predetermined tension to the chain. Therefore, the chain passage has to be formed with a larger space outside of the slack side than the space outside of the tensile side of the chain. On the other hand, there is a case in which the timing chain is arranged at that side of one of the V-shaped cylinders, which is different from the side of the other cylinder, such that it is directed at a right angle with respect to a crankshaft. In the so-called "tandem V-engine" having its respective cylinders inclined in the longitudinal direction, for example, timing chains are sometimes arranged at the righthand side of one cylinder and at the lefthand side of the other cylinder, respectively. In the so-called "transverse V-engine" having its respective cylinders inclined in the transverse direction, on the contrary, timing chains are sometimes arranged at the front side of one cylinder and at the rear side of the other cylinder, respectively.
In such engines, if the slack side of the timing chain of one cylinder is positioned in the V-shaped space of two cylinders, the slack side of the timing chain of the other cylinder is positioned at the outer side which is opposite to the side facing that space. In other words, the tensile side of one cylinder and the slack side of the other cylinder are positioned at the sides facing that space. As a result, the conventional cylinder block, in which the larger space is formed only outside of the slack side of each timing chain, has to be formed into a different shape for each cylinder so that a completely different mold has to be prepared because of a slight difference in the shapes. Moreover, the number of different parts is so increased that their management becomes troublesome.